diff --git a/plugins/windowsystem/windowsystem.cpp b/plugins/windowsystem/windowsystem.cpp
index df4c55388c..b73ac62ac5 100644
--- a/plugins/windowsystem/windowsystem.cpp
+++ b/plugins/windowsystem/windowsystem.cpp
@@ -107,7 +107,7 @@ QPoint WindowSystem::desktopToViewport(int desktop, bool absolute)
     return QPoint();
 }
 
-#ifndef KWINDOWSYSTEM_NO_DEPRECATED
+#if KWINDOWSYSTEM_BUILD_DEPRECATED_SINCE(5, 0)
 WId WindowSystem::groupLeader(WId window)
 {
     Q_UNUSED(window)
@@ -287,7 +287,7 @@ QList< WId > WindowSystem::stackingOrder()
     return {};
 }
 
-#ifndef KWINDOWSYSTEM_NO_DEPRECATED
+#if KWINDOWSYSTEM_BUILD_DEPRECATED_SINCE(5, 0)
 WId WindowSystem::transientFor(WId window)
 {
     Q_UNUSED(window)
diff --git a/plugins/windowsystem/windowsystem.h b/plugins/windowsystem/windowsystem.h
index f2abf5c437..1e97ab3d69 100644
--- a/plugins/windowsystem/windowsystem.h
+++ b/plugins/windowsystem/windowsystem.h
@@ -23,6 +23,15 @@
 
 #include <QObject>
 
+// Compat with KF < 5.64
+#ifndef KWINDOWSYSTEM_BUILD_DEPRECATED_SINCE
+#ifndef KWINDOWSYSTEM_NO_DEPRECATED
+#define KWINDOWSYSTEM_BUILD_DEPRECATED_SINCE(x, y) 1
+#else
+#define KWINDOWSYSTEM_BUILD_DEPRECATED_SINCE(x, y) 0
+#endif
+#endif
+
 namespace KWin
 {
 
@@ -44,7 +53,7 @@ public:
     void setOnAllDesktops(WId win, bool b) override;
     void setOnDesktop(WId win, int desktop) override;
     void setOnActivities(WId win, const QStringList &activities) override;
-#ifndef KWINDOWSYSTEM_NO_DEPRECATED
+#if KWINDOWSYSTEM_BUILD_DEPRECATED_SINCE(5, 0)
     WId transientFor(WId window) override;
     WId groupLeader(WId window) override;
 #endif